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用低频扭摆观察了等原子比的NiTi合金在发生正、反马氏体相变时的内耗变化。在室温附近,降温测量到0℃以下,逆转升温测量到60℃以上的过程中,从500℃退火炉冷的试样仅分别观察到单一正马氏体转变内耗峰和反马氏体转变内耗峰。同一试样,悬在扭摆仪中就地经过多次热循环测量,随后在降温测量中逐步发展出来一个位于正马氏体转变峰前的内耗峰,对应于前人在淬火试样中所观察到的予马氏体转变内耗峰,并在频率温度曲线上有对应的明锐频率极小。本工作也观察了降温测量中止的温度对随后逆转升温测量所得的反向转变内耗峰的影响。发现降温测量时,测量中止温度由予马氏体转变温区降至马氏体转变温区时,逆转升温测量所出现的两个对应反相变内耗峰之间有相互消长关系,本文定性地讨论了所观察到的现象。
The internal friction change of NiTi alloys with equal atomic ratio during the occurrence of positive and anti-martensitic transformation was observed by low-frequency torsion. Near room temperature, the cooling measured below 0 ℃, the reverse temperature measurement to 60 ℃ above the process, from the furnace annealing at 500 ℃ were observed only a single positive martensitic transformation within the peak friction and anti-martensitic transformation internal friction peak. The same sample, hanging in the torsion pendulum in place after repeated thermal cycling measurements, and then gradually developed in the cooling measurement is located in front of a positive martensitic transformation peak internal friction peak, corresponding to the previous observation in the quenched sample To the martensitic transformation within the consumption peak, and in the frequency temperature curve has a corresponding minimum sharpness frequency. This work also observed the effect of the temperature at which the cooling measurement was stopped on the internal friction peak of the reverse transformation resulting from the subsequent reversal of the heating measurement. Found cooling measurement, the measurement stop temperature from the pre-martensitic transformation temperature zone to the martensitic transformation temperature zone, reverse heating measurement of the two corresponding inverse phase change within the friction peak between consumption and growth of this paper qualitatively discussed The observed phenomenon.